Ity of Modes in a Parallel Plate, Anisotropic Waveguide Using a Modified, Coordinate Transformation

The excitation of forward and backward, Electromagnetic (EM) modes and fields in an anisotropic, parallel plate waveguide (meeting Dirichlet and Neumann boundary conditions), is studied, using a modified coordinate transformation which reduces Maxwell’s equations to the form of a Helmholtz wave equation satisfying Dirichlet and mixed-partial derivative boundary conditions. The EM modes and fields of the system are excited by a novel, slanted electric surface current excitation whose slant angle has been chosen to coincide with the surfaces of constant phase of the anisotropic modes which may propagate in the waveguide. Also presented in the paper, for comparison purposes, is the EM field excitation analysis corresponding to an isotropic parallel plate waveguide whose waveguide characteristics are close to those of the anisotropic waveguide. Several results are presented herein, including; a novel waveguide modal characteristic equation analysis used to determine the propagating and complex (or non propagating) modes that may exist in an anisotropic waveguide system, a novel study of backward-forward modal orthogonality based on the complex Poynting theorem and a power-energy reaction integral equation, descriptions of the matrix analyses used to determine the EM fields excited in the anisotropic and isotropic waveguide systems under consideration, and several numerical results. Corresponding author: J. M. Jarem ([email protected]).